This invention relates generally to bicycles, and more particularly the invention relates to a bicycle having arm assisted drive.
A number of designs have been proposed for arm assisted drive of the conventional foot pedal powered bicycle. Many patents have issued which describe hand cranks used to provide power to the front wheel via a continuous chain drive. Problems attendant with all of these arrangements include difficulty in steering and the added weight of the crank mechanism.
Other patents describe arm assisted drives not requiring a continuous chain. U.S. Pat. No. 4,733,880 describes the use of hand pedals which are mechanically coupled to the foot pedal by tension lines through pulleys. An unconventional dual handlebar is required which complicates steering. Further, the reciprocating movement of the handlebars is continuous when the foot pedals are in use.
U.S. Pat. No. 4,685,692 uses rotary hand cranks in addition to a conventional handlebar for steering. The hand cranks rotate a flexible shaft which is coupled to the shaft of a foot powered sprocket wheel to thereby provide a supplemental drive to the sprocket wheel. Again, there is no on-demand use of the hand crank since the crank is always turning when the foot pedals are turning.
U.S. Pat. No. 4,726,600 discloses a linkage mechanism whereby vertically reciprocating movement of the handlebars is coupled to the foot pedals. Again, the handlebars are always moving when the foot pedals are rotating.
The present invention provides an arm assisted bicycle drive which overcomes disadvantages of the prior art.